Department of Mechanical Engineering, The George Washington University, Washington, DC 20052, USA.
Bioinspir Biomim. 2011 Mar;6(1):014001. doi: 10.1088/1748-3182/6/1/014001. Epub 2010 Dec 15.
The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 µN mm(-1) h(-1). For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm(-1).
昆虫翅膀的刚性通常通过实验测量来确定。此类实验是在从昆虫身上取下的翅膀上进行的。然而，翅膀会干燥，这通常会导致其刚性增加。尽管这种干燥效应是众所周知的，但对干燥昆虫翅膀的刚性变化率进行全面研究将有助于实验计划以及解释此类实验的数据。本通讯对逐渐干燥的粉蝶前翅（Vanessa cardui）的质量和刚度变化进行了全面的实验分析。在 24 小时内，每隔 10 分钟同时测量五只蝴蝶的前翅的质量和刚度。平均结果表明，在此期间，翅膀质量以 21.1%的指数速率下降，时间常数为 9.8 小时，而翅膀刚度以 23.4 µN mm(-1) h(-1)的线性速率增加 46.2%。对于一只蝴蝶的前翅，实验进行了一周，结果表明，翅膀质量以 52.2%的指数速率下降，时间常数为 30.2 小时，直到达到 2.00 毫克的稳定水平，而翅膀刚度以 90.7%的指数速率增加，直到达到 1.70 mN mm(-1)的稳定水平。
